Tenke advances Alto Rico (March 19, 2003)

Vancouver — Tenke Mining (TNK-T) has tabled encouraging early results from its exploration program at its low sulphidation epithermal gold-silver Alto Rico prospect in Patagonai, Argentina.

Ongoing exploration has outlined large co-incident geophysical and geochemical anomalies at the 42.7 sq. km Alto Rico property in the province of Santa Cruz. Induced polarization and resistivity surveys totalling 62 line km have been completed. Resistor and chargeability anomalies span an area of 3 km by 1 km and are along trend with the main vein and stockwork zone. In addition, 40 trenches totalling 2,500 metres have been dug and sampled.

Sampling has returned assay values that ranged 0.35-to-4.5 grams gold per tonne in veins and up to 2.0 grams gold in stockwork. Mercury anomalies range from 5,400-to-26,500 ppb; arsenic ranges from 180-to-951 ppm and antimony ranges from 29-to-117 ppb.

Tenke states that mineralization exhibits banded textures with open-space fillings. Other features such as bladed calcite replaced by quartz suggest conditions near the top of an epithermal system above the boiling zone a level at which pressure and temperature conditions favor precious metal precipitation.

The Alto Rico vein system has been traced for over 12 km and is composed of five principal sub-parallel veins that trend to the northeast. These veins vary between 1 and 10 metres in width with an average outcrop width of 3 metres. They converge on a hill that shows signs of extensive stockwork, silicification, acid leaching and argillic alteration. Tenke states that mineralization is hosted in permeable dacitic to andesitic tuffaceous rocks. Fieldwork is expected to be completed by early April and a drill program is anticipated by the end of that month.

Meanwhile, 30 km to the northwest, Tenke is working on a similar prospect dubbed El Macanudo. This property is also part of the overall Alto Rico project. El Macanudo hosts a thick (up to 40 metres) and extensive (at least 4 sq. km.) sinter sequence hosted in volcanic tuffs and ignimbrites.

Sinters represent indicators of low temperature silica precipitation above active epithermal systems that may have the potential to host precious metal deposits. The area hosts strong mercury, arsenic, manganese and calcium anomalies which are now being systematically sampled. Initial geophysical surveys (induced polarization/resistivity) indicate a possible feeder structures below the sinter.